Fork lift trucks, such as turret stockpicker trucks, comprising a power unit assembly detachably connected to a main frame assembly are known in the prior art. In such a truck, the power unit assembly comprises a power unit base, at least one wheel coupled to the base and being driven by one or more traction motors, a battery for providing power to the traction motor(s), and a traction motor control module(s) for controlling the operation of the traction motor(s). A first hydraulic motor/pump assembly and at least one manifold valve block are also mounted on the power unit base. The main frame assembly comprises a main frame base, a mast assembly comprising a fixed first mast and a second mast movable relative to the first mast, a piston/cylinder unit for effecting movement of the second mast relative to the first mast, a second hydraulic motor/pump assembly for providing pressurized fluid to the piston/cylinder unit for effecting movement of the second mast, and a carriage assembly coupled to said second mast for movement with the second mast. Further provided on the main frame base is a hydraulic fluid reservoir and at least one manifold valve block.
Because the first hydraulic motor/pump assembly and at least one manifold valve block are mounted on the power unit base and the fluid reservoir is mounted on the main frame assembly, hydraulic tubes/lines extend between the power unit and main frame assemblies. Hence, in order to separate those assemblies, such as for shipping the truck, one or more of the hydraulic tubes/lines extending between the power unit assembly and the main frame assembly must be disconnected. Such a disassembly operation is disadvantageous due to its complexity. Also, disconnecting one or more hydraulic lines/tubes increases the risk that those lines/tubes may become contaminated with moisture, dirt, air, etc. A further disadvantage to having the first hydraulic motor/pump assembly mounted on the power unit is that it is located in close proximity to many of the electronic and electrical components. As a result, there is an increased risk that those electronic and electrical components may be contaminated with hydraulic fluid or dirt accumulated on the first hydraulic motor/pump assembly mounted to the power unit base.